نتایج جستجو برای: solvent free
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چکیده : * در یک واکنش تک ظرفی و با استفاده از واکنش آلدهید های آروماتیک و 3- متیل 1- فنیل پیرازولین-5- ان با نسبت مولی 1:1، ساختارهای هتروسیکل پیرازول سنتز شد. از مزایای آن، انجام واکنش در دمای اتاق، عدم نیاز به کاتالیزور، بازده بالای واکنش، استفاده از آب بعنوان حلال سبز و بی خطر به جای حلال های آلی وسمی می باشد . * توانستیم با استفاده از ملدرام اسید ومشتقات 2- هیدروکسی بنزآلدهید، ترکی...
The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aq...
Solvent collisions can often mask initial disposition of energy to the products of solution-phase chemical reactions. Here, we show with transient infrared absorption spectra obtained with picosecond time resolution that the nascent HCN products of reaction of CN radicals with cyclohexane in chlorinated organic solvents exhibit preferential excitation of one quantum of the C-H stretching mode a...
selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. this catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...
poly(4-vinylpyridine)-supported copper iodide nanoparticles is reported as a new, green and recyclable catalyst for the synthesis of aryl-14h-dibenzo [a-o] xanthenes under solvent-free conditions. this catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of their efficiency.
This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...
A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this pro...
ABSTRACT: Chemical composition of Lavandula angustifolia was studied by solvent free microwave extraction (SFME) and hydrodistillation (HD) methods. 1, 8-cineole (42.7% and 37.9%), Camphor (26.1% and 21.3%) and Borneol (31.2% and 21.6%) were the major compounds that obtained by SFME and hydrodistillation, respectively. The antibacterial activity of extracted oils was investigated against Gram-p...
We present a new approach for predicting solvation free energies in nonaqueous solvents. Utilizing the corresponding states principle, we estimate solvent Lennard-Jones parameters directly from their critical points. Combined with atomic solutes and the pressure corrected three-dimensional reference interaction site model (3D-RISM/PC+), the model gives accurate predictions for a wide range of n...
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